"Learn to use 3skeng" files (learning material in SketchUp file format)
Download an archive that contains all "learn to use 3skeng" files (SketchUp format and pdf for scene descriptions).Learn to use (1)-(7) 3skeng.zip

Video tutorials and "learn to use 3skeng" files (SketchUp format) that show you how to use 3skeng tools and their features: